8 y/o broke out in hives after1st time bee sting. now epi-pen must be used every sting. will he grow out of this? how can we test severity of allergy?

See an allergist: If it truly was his very first bee sting, it is very unlikely he is allergic--the immune system needs to see something at least once before it can generate an allergic reaction. Your allergist can perform testing to determine if he is actually allergic to stings. If so, he will not likely outgrow it. But, allergy shots can help prevent anaphylaxis. Talk with an allergist about your concerns.

Mgt: It would be helpful to review and a virtual appointment may be booked online. Were there multiple stings? Do you live in an area with bees nests? The EPI Pen is used for patients at high risk of a severe reaction. This is a helpful website: http://www.mayoclinic.org/diseases-conditions/bee-stings/basics/treatment/con-20034120